A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of skin lesions. It gives a clear definition of what skin lesions are. This follows the rule of Topic Sentence. Why other lines are not chosen? Paragraph 2 starts with 'They', which is a pronoun and needs context. Paragraph 3 starts with 'Skin lesions that are benign', which is specific and not general. Paragraph 4 starts with 'Most benign lesions', which also refers back to a specific type of lesion.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about benign lesions. It gives a conclusion about their treatment needs. This follows the rule of Conclusive Words, as it summarizes the main points.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues to talk about skin lesions. It uses the Connector strategy by starting with 'They', which refers back to 'skin lesions'. This shows a logical flow of ideas.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it gives more information about skin lesions. It follows the Broader to Specific Strategy. Paragraph 2 talks about skin lesions in general, and Paragraph 3 specifies benign lesions.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it talks about benign lesions. It uses the Logical Order strategy, as it explains what happens with benign lesions after defining them.